I believe you are referring to Nucleic acids.
        
             
        
        
        
First one i thnk???
brainliest
        
             
        
        
        
according to sciencethreads.com 
it states the following pros and advantages of fossil fuels.. 
<em><u>1)Fossil fuels have a very high calorific value. </u></em>
<em><u>2)the energy produced by fossil fuels is greater than that produced by an equivalent amount of other energy resource.</u></em>
<em><u>3)Systems are set up to process and utilize oil and gas
</u></em>
<em><u>4)Widely available around the globe
</u></em>
<em><u>5)low cost per unit energy
</u></em>
<em><u>6)Refineries, transportation, and plastics all rely heavily on oil and gas
</u></em>
<em><u>7)High energy output
</u></em>
<em><u>8)Employs millions of people globally
</u></em>
<em><u>9)The primary source of all plastics</u></em>
hope this helps :)
 
        
             
        
        
        
Answer:
The correct answer is B. DNA helicase first unwinds the double helix around the +1 site.
Explanation:
The helicase is an enzyme that specifically breaks the hydrogen bonds of the bases in the transcription process. As E. Coli is a prokaryote, then, the transcription only occurs in one point of the circular DNA. The promoter region indicates where the DNA polymerase has to start replicating and the Topoisomerase unwinds the parts of the DNA that are being excessively twisted because of the separation of the two strands.